Gravity flow dryer for particulate material having channelized discharge

Abstract

A gravity-flow grain dryer for particulate material comprises a generally vertical drying column having first and second opposed spaced perforate walls, the column being adapted to receive particulate material and direct the material through the dryer. An input is provided for introducing moist particulate material into a top portion of the column and a discharge mechanism is provided for removing dried particulate material from a bottom portion of the column. A blower and heater are also provided for passing drying air into the column through the first perforate wall and out through the second perforate wall, the air drying the material within the column. A dividing wall extends between the perforate walls for dividing at least a portion of the column into at least two channels, of the channels containing a discharging mechanism for removing particulate material from the channel. A first discharge mechanism is associated with a first of the channels and a second discharge mechanism is associated with a second of the channels, the first channel being adjacent the first perforate wall and the first discharge mechanism is adapted to discharge particulate material at a rate faster than the second discharge mechanism.

I claim: 
     
       1. A gravity flow dryer for particulate material comprising: a generally vertical drying column having first and second opposed spaced walls, a corresponding portion of each of said walls including perforations therein, the column being adapted to receive particulate material at the top and direct the material through the dryer to the bottom and being unrestricted in the column to the flow of particulate material so as to permit particulate material to flow from the second wall toward the first wall as the particulate material passes down the column;   means for introducing moist particulate material into a top portion of the column;   means for passing drying air into the column through the perforate portion of the first wall and out of the column through the perforate portion of the second wall for drying the material in a treating zone in the column;   output means located below the perforate portion of the column for removing dried particulate material from the bottom of the column below the treating zone in and including a first discharge means at the bottom of the column and a second discharge means at the bottom of the column, the first discharge means being adjacent the first wall and the first discharge means being adapted to discharge particulate material at a rate faster than the second discharge means to provide a differential grain flow in the unrestricted column in the treating zone for more particulate material passing through the column to be discharged through the first discharge means, whereby the faster dried grain adjacent the first wall in the column passes through the column faster for a channelized discharge through the discharge means.   
     
     
       2. The dryer as recited in claim 1 wherein drying column is substantially rectangular in cross section and at least one of the opposed spaced walls of the drying column is gradually tapered outwardly from top to bottom so that the column has a greater width between the opposed spaced walls at the bottom than at the top. 
     
     
       3. The dryer as recited in claim 1 wherein the drying column having the first and second opposed walls provides a first drying column, the dryer further including: a second generally vertical drying column substantially the same as the first drying column, the first and second drying columns being spaced apart to provide a plenum chamber between the perforate portions of the first walls of each column, the drying air passing into the plenum chamber before entering the perforate portions of the first walls of the drying columns;   a second generally vertical solid partition at the bottom portion of the second column extending generally parallel to but below the perforate portion of said walls of the second column, the second partition for dividing the particulate material directed through the second column into first and second channels after said particulate material has been exposed to said drying air; and   third discharge means associated with the first channel of the second column and fourth discharge means associated with the second channel of the second column, the third discharge means being adjacent the first wall of the second column and being adapted to discharge particulate material at a rate faster than the fourth discharge means.   
     
     
       4. The dryer as recited in claim 2 wherein the wall gradually tapered outwardly is the first wall. 
     
     
       5. A gravity flow dryer for particulate material comprising: a generally vertical drying column having first and second opposed spaced walls, a corresponding portion of each of said walls including perforations therein, the column being adapted to receive particulate material and direct the material through the dryer;   means for introducing moist particulate material into a top portion of the column;   means for passing drying air into the column through the perforate portion of the first wall and out of the column through the perforate portion of the second wall for drying the material in the column;   means located below the perforate portion of the column for removing dried particulate material from the bottom of the column and including a generally vertical solid partition extending generally parallel to but below the perforate portion of the column walls for dividing the particulate material directed through the column into first and second channels after said particulate material has been exposed to said drying air, at least a portion of the partition being adjustable to vary the flow of material that passes through the channels;   a first discharge means associated with the first channel and a second discharge means associated with the second channel, the first channel being adjacent the first wall and the first discharge means being adapted to discharge particulate material at a rate faster than the second discharge means.   
     
     
       6. The dryer as recited in claim 5 wherein the relative channel sizes and the relative rates of discharge of the first and second discharge means are coordinated to provide for preferred drying of particulate material. 
     
     
       7. A gravity flow dryer for particulate material comprising: a generally vertical drying column having first and second opposed spaced walls, a corresponding portion of each of said walls including perforations therein, the column being adapted to receive particulate material and direct the material through the dryer, the dryer column having the first and second opposed walls providing a first drying column;   means for introducing moist particulate material into a top portion of the column;   means for passing drying air into the column through the perforate portion of the first wall and out of the column through the perforate portion of the second wall for drying the material in the column;   means located below the perforate portion of the column for removing dried particulate material from the bottom of the column and including a generally vertical solid partition extending generally parallel to but below the perforate portion of the column walls for dividing the particulate material directed through the column into first and second channels after said particulate material has been exposed to said drying air, a first discharge means associated with the first channel and a second discharge means associated with the second channel, the first channel being adjacent the first wall and the first discharge means being adapted to discharge particulate material at a rate faster than the second discharge means;   a second generally vertical drying column substantially the same as the first drying column, the first and second drying columns being spaced apart to provide a plenum chamber between the perforate portions of the first walls of each column, the drying air passing into the plenum chamber before entering the perforate portions of the first walls of the drying columns;   a second generally vertical solid partition at the bottom portion of the second column extending generally parallel to but below the perforate portion of said walls of the second column, the second partition for dividing the particulate material directed through the second column into first and second channels after said particulate material has been exposed to said drying air, at least a portion of the second partition being adjustable to vary the flow of material that passes through the channels of the second column; and   third discharge means associated with the first channel of the second column and fourth discharge means associated with the second channel of the second column, the third discharge means being adjacent the first wall of the second column and being adapted to discharge particulate material at a rate faster than the fourth discharge means.   
     
     
       8. The dryer as recited in claim 7 wherein the adjustment of the second partition and the relative rates of discharge of the third and fourth discharge means are coordinated to provide for preferred drying of particulate material.